Question

the atomic number of barium is 56 what do you know about the subatomic particles in an atom of this element

Answer 1

If this atom is a neutral atom, the subatomic particles would be 56 protons, 56 neutrons, and 56 electrons.

Answer 2

Answer is 56 protons and 56 electrons.

Explanation;

Atomic number is equal to number of protons. Hence, when the atomic number is 56, it means that atom has 56 protons.

When the element is in neutral state, number of protons = number of electrons. Hence, we can say that barium atom has 56 electrons.

But same element can have different number of neutrons. Those are called isotopes. Hence, we cannot say that there are 56 neutrons in barium atom without having its mass number. (Mass number = number of protons + number of neutrons)